Recording/reproduction apparatus with an integrated inductive write, magnetoresistive read head

ABSTRACT

In a recording/reproduction apparatus equipped with an integrated head comprising a thin film inductive write element and a MR read element and mounted on a head slider which is arranged to be rotatable about a point so as to be rotationally accessible to tracks of a disk serving as a recording medium to make yaw angles with respect to tangents of the tracks, the inductive write element and the MR read element are arranged so that a magnetic center line of the MR read element which extends in directions perpendicular to track crossing directions is separated from a geometric center line of the MR write element which extends in directions perpendicular to the track crossing directions. The separation between the inductive write element and the MR read element is determined as the result of a multiplication of 1/2 of the sum of the sine of the slider yaw angle with respect to the tangent of the innermost track on the disk and the sine of the slider yaw angle with respect to the tangent of the outermost track by the distance between a gap of the inductive write element and the center of the MR read element. This arrangement allows minimizing the off-track between the write and read modes which occurs due to the yaw angles.

This is a divisional of application Ser. No. 08/687,961 now U.S. Pat.No. 5,691,862 filed Jul. 29, 1996, which is a Divisional of applicationSer. No. 08/302,531 now U.S. Pat. No. 5,596,463 filed Sep. 8, 1994.

BACKGROUND OF THE INVENTION

The present invention relates to a recording/reproducing apparatus forwriting and reading signals on and from a recording medium, and moreparticularly to an integrated thin film inductive write,magnetoresistive (MR) read head (which will hereinafter be referred toas an integrated head) used in connection with a so-called rotarycylinder comprising a plurality of disk-like recording media rotatablysupported on a rotary spindle and to a track arrangement of thedisk-like recording medium of the rotary cylinder.

Recently, improvement for signal recording and reproduction systems suchas a so-called hard disk apparatus is being made for increasingrecording density and promoting write/read efficiency purposes, and anintegrated head has been developed which comprises a thin film inductiveelement for a write mode and an MR element for a read mode and which ismounted on a head slider constructed to floats on a so-called airbearing principle. For positioning such an integrated head to one of aplurality of rotary disks coaxially arranged to have a cylindricalconfiguration as a whole, there is generally being employed a swing typeaccess mechanism comprising a swing arm which carries the head sliderwith the integrated head at its one end and rotates about the other endso that the integrated head moves to and separates from the rotary disk.

There are some problems which arise with such a recording/reproductionsystem, however, particularly when using small form factor disks whosediameters are 3.5 inches or less as recording media. A serious problemis an occurrence of a yaw angle (skew misalignment) which arises due tothe movement of the integrated head to the disk in an arc made inaccordance with the movement of the swing type access mechanism. A largeyaw angle reduces the effective track widths on the disk as well asdecreasing the floating amount of the head slider. Accordingly, there isa limit to the yaw angle and the limit is desirable to be 15° to 20°. Inaddition, there is a separation (generally about 10 μm) in positionbetween the inductive write element and MR read element. Subject to alarge yaw angle, the on-track positions of the inductive write elementand the MR read element differ from each other between the write andread modes, creating an off-track state. This off-track increasesreproduction errors and lowers the throughput. Further, the off-trackcauses a problem in sector identification and others. In this system therecording into a data field is required to be made immediately after thereading of identification data from an information identification fieldbecause the recording and reproduction are made with different heads.When an offset occurs between the magnetic center lines of the MR readelement and inductive write element when the yaw angle is relativelylarge, difficulty is actually encountered to accurately recognize thesector number and others.

Elimination of such an off-track state has been attempted by minimizingthe off-track amount at the outermost position of the disk where the yawangle becomes the largest or reducing the separation between theinductive write element gap and the MR read element. However in fact theoffset amount of an information identification field from a data fieldbecomes large in the case of merely minimizing the offset amount so thatdifficulty is made to recognize an identifier (identificationinformation) to reproduce data, and further there is a limit to thereduction of the separation therebetween from the viewpoint of therecording characteristic of the inductive write element and the shieldcharacteristic of the MR read element.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide arecording/reproduction apparatus which is capable of minimizing theoff-track between recording and reproduction due to the occurrence ofthe slider yaw angle irrespective of the separation between theinductive write element and magnetoresistive read element withoutsacrificing the track capacity.

This and other objects which will become apparent as the descriptionproceeds. In accordance with the present invention there is provided anarrangement of a thin film inductive write element and a MR read elementof an integrated head mounted on a head slider which is arranged to berotatable about a point so as to be rotationally accessible to tracks ofa disk serving as a recording medium to make yaw angles with respect totangents of the tracks. A feature of this invention is that theinductive write element and the MR read element are arranged so that amagnetic center line of the MR read element which extends in directionsperpendicular to track crossing directions is separated from a geometriccenter line of the MR write element which extends in directionsperpendicular to the track crossing directions, and the separationtherebetween is determined as the result of a multiplication of 1/2 ofthe sum of the sine of the slider yaw angle with respect to the tangentof the innermost track on the disk and the sine of the slider yaw anglewith respect to the tangent of the outermost track by the distancebetween a gap of the inductive write element and the center of the MRread element. When defining the arrangement of the inductive writeelement and the MR read element by a geometric relationship, theseparation between the inductive write element and the MR read elementis determined on the basis of 1/2 of the sum of the sine of the slideryaw angles with respect to the tangents of the innermost and outermosttracks, the distance between a gap of the inductive write element andthe center of the MR read element and the height of the MR read elementfrom a surface of the head slider.

Further, according to this invention there is provided an arrangement ofinformation identification fields and data fields in tracks on the diskwhich is determined in connection with an integrated head comprising athin film inductive write element and a MR read element. The centerlines of the information identification fields which extend indirections perpendicular to track crossing directions are shifted bypredetermined distances from center lines of the data fields whichextend in directions perpendicular to the track crossing directions soas to make deviations in the track crossing directions between thecenter lines of information identification fields and the center linesof the data fields. The deviations are determined in accordance with thepositional relationship in the track crossing directions betweenmagnetic center lines of the inductive write element and the MR readelement so as to vary successively to increase toward the innermost oroutermost portion of the disk or increase from the middle portion towardthe innermost and outermost portions.

BRIEF DESCRIPTION OF THE DRAWINGS

The object and features of the present invention will become morereadily apparent from the following detailed description of thepreferred embodiments taken in conjunction with the accompanyingdrawings in which:

FIG. 1 is a schematic illustration of an arrangement of an integratedhead;

FIG. 2 is an illustration of a head slider equipped with the integratedhead;

FIG. 3 is an illustration for describing the occurrences of skews of thehead slider with respect to a disk;

FIG. 4 shows an reproduction characteristic of an MR read element fordescribing a magnetic center of the MR read element;

FIG. 5 is an illustration for describing a magnetic relationship betweena thin film inductive write element and an MR read element;

FIG. 6 is an illustration for describing a geometric relationshipbetween a thin film inductive write element and an MR read element;

FIG. 7 is an illustration for describing an integrated head according toa first embodiment of this invention;

FIGS. 8 to 10 are illustrations for describing the relationship betweentracks of a disk and the integrated head according to the embodiment ofthis invention;

FIG. 11 is a perspective view for describing an integrated headaccording to a second embodiment of this invention;

FIG. 12 illustrates a track layout on a disk of a rotary cylinderaccording to a third embodiment of this invention;

FIG. 13 is a graphic illustration for describing deviations between aninformation identification field and a data field at every position of adisk in the third embodiment;

FIG. 14 shows a track layout on a disk according to a fourth embodimentof this invention;

FIG. 15 is a graphic illustration for describing deviations between aninformation identification field and a data field at every position of adisk in the fourth embodiment;

FIG. 16 shows a track layout on a disk according to a fifth embodimentof this invention;

FIG. 17 is a graphic illustration for describing deviations between aninformation identification field and a data field at every position of adisk in the fifth embodiment; and

FIG. 18 is an illustration for describing the relationship in positionbetween servo surface servo signal fields and recording fields when thefifth embodiment is applied to a recording/reproduction system equippedwith a head positioning servo surface.

DETAILED DESCRIPTION OF THE INVENTION

A description of an integrated head will first be made below withreference to FIGS. 1 and 2 illustrating a structure of the integratedhead and illustrating a magnetic head slider which is equipped with theintegrated head, respectively. In FIGS. 1 and 2, the integrated head 1comprises a thin film inductive write element 2 made up of an upper polesection 3 and a lower pole section 4, and an MR read element 10sandwiched between upper and lower MR shield sections 16 and 17 forreduction of magnetic noises. The upper and lower pole sections 3 and 4are arranged in parallel to make a magnetic gap 5 therebetween. Theinductive write element 2 and the MR read element 10 are located so thatthe inductive write element gap 5 is separated by a predetermineddistance 9 from the center of the MR read element 10. Here, thin filmcoils and others are omitted for brevity. The integrated head 1 isformed within an alumina protective layer 18 on a trailing edge surfaceof an air bearing surface (ABS) 19 of a magnetic head slider 22 asschematically shown in FIG. 2. The head slider 22 is arranged so as tofloat above a disk on the principle of air bearing.

As illustrated in FIG. 3, the magnetic head slider 22 is arranged to berotatable about a pivot 25 through a swing type access mechanism (notshown). In the case of driving the magnetic head slider 22 through theswing type access mechanism, when the integrated head 1 reaches theinnermost position (including the innermost track) 23 of the disk, aninnermost yaw angle (P1) 7 is made between the longitudinal directions(the line connecting the center of the pivot 25 with the center of themagnetic head slider 22) of the magnetic head slider 22 and thegeometric tangent of the innermost portion 23 of the disk, and when theintegrated head 1 is at the outermost position (including the outermosttrack) 24 of the disk, an outermost yaw angle (P2) 6 also occurs betweenthe longitudinal directions of the magnetic head slider 22 and thegeometric tangent of the outermost portion 24 thereof. Here, the yawangle is measured clockwise with respect to the track tangent so as totake plus and minus signs.

FIG. 4 shows an ideal off-track characteristic of the MR read element10, wherein the horizontal axis indicates the off-track amount and thevertical axis denotes the reproduction output from the MR read element10. In the integrated heads, for improving the off-track characteristicthe width (track width) of the inductive write element upper polesection 3 is generally set to be larger than the width of the MR readelement 10, and hence the reproduction output of the MR read element 10with respect to the off-track amount varies to form a trapezoid asillustrated in FIG. 4. In this case, the magnetic center line 20 of theMR read element 10 corresponds to a center of the maximum output portion21 of the trapezoidal off-track characteristic.

FIG. 5 shows the relationship in magnetic position between the inductivewrite element 2 and the MR read element 10. In FIG. 5, numeral 28indicates a magnetic center line 28 of the inductive write element 2 andnumeral 20 denotes a magnetic center line 20 of the MR read element 10.The magnetic center line 28 of the inductive write element 2 can beconsidered to be coincident with the geometric center line thereof ifassuming that the asymmetries of the head erase bands and fringings areextremely small. The magnetic center line 20 of the MR read element 10is shown on the assumption that the MR read element 10 is at theon-track position corresponding to the center of the maximumreproduction output portion 21 as illustrated in FIG. 4. In this case,an offset (slippage) amount 26 in the track crossing directions betweenthe magnetic center line 28 passing through the inductive write elementgap 5 and the magnetic center line 20 of the MR read element 10 isdefined as a magnetic difference between the write and read modes. Onthe other hand, FIG. 6 shows a slippage between the geometric centerline 29 passing through the inductive write element gap 5 and thegeometric center line 30 of the MR read element 10. This offset isdefined as a geometric difference 31 between the write and read modesdifferent from the magnetic difference 26 in FIG. 5.

FIG. 7 is a schematic illustration of an integrated head according to afirst embodiment of this invention when being viewed from the disk sideand when being at an outermost position of a disk traveling in thedirection indicated by an arrow. In FIG. 7, the MR read element 10 isplaced at a position separated by a distance (S) 9 from the head gap 5of the inductive write element 2 toward the ABS 19 side. When theinductive write element 2 is taking an on-track state in a write mode,the center line 29 of the inductive write element 2 is coincident withthe center line 8 of a data track on the disk which extends in parallelto the disk traveling direction. On the other hand, although beingoriginally arranged to coincide with the magnetic center line 29 of theinductive write element 2, due to occurrence of the yaw angle 6 at theoutermost position of the disk, the magnetic position of the MR readelement 10 is shifted and offset to the inner side (to the right side inthe illustration) of the disk as illustrated at numeral 12. This offsetdistance from the center line 8 of the data track assumes the result(solution) of a multiplication of the separation 9 by the sine of theoutermost yaw angle 6. Here, calculating under the condition that theinnermost yaw angle=0°, the outermost yaw angle=15° and the separation=8microns, the offset distance becomes about 2 microns which cannotactually be ignored considering the recent high-density recording. Onthe other hand, if setting the magnetic position of the MR read element10 at an on-track position 15 in consideration of immediately enteringinto a read mode, when the integrated head 1 is moved up to theinnermost position of the disk with the separation 9 between theinductive write element 2 and the MR read element 10 being fixed, anoffset of the magnetic position of the MR read element 10 toward theouter side of the disk similarly develops by the result of amultiplication of the sine of the innermost yaw angle 7 by theseparation 9.

For improving these points, the first embodiment of this inventionfeatures the following arrangement of the integrated head. That is, therelationship in magnetic position between the inductive write element 2and the MR read element 10 is determined on the basis of amultiplication of 1/2 of the sum of the sine of the innermost yaw angle7 and the sine of the outermost yaw angle 6 by the geometric separation9 between the inductive write element 2 and the MR read element 10. Morespecifically, further referring to FIG. 5 the inductive write element 2and the MR read element 10 are placed so that the positional difference26 in the track crossing directions between the magnetic center lines 28and 20 of the inductive write element 2 and the MR read element 10substantially becomes equal to the result of a multiplication of 1/2 ofthe sum of the sine of the innermost yaw angle 7 and the sine of theoutermost 25 yaw angle 6 by the geometric separation 9 between theinductive write element 2 and the MR read element 10. When expressingthe positional difference OFFSET between the elements 2 and 10 by anequation, it becomes as follows:

    OFFSET=1/2×{sin (P1)+sin (P2)}×S               (1)

where P1=the slider yaw angle at the innermost track, P2=the slider yawangle at the outermost track, sin(P1)=the sine of the slider yaw angleP1, sin(P2)=the sine of the slider yaw angle P2, and S=the separationbetween the magnetic gap 5 of the inductive write element 2 and thecenter of the MR read element 10.

When 1/2×(sin(P1)+sin(P2)) is defined as an angle offset value P, theabove-mentioned equation (1) becomes P×S.

Here, according to a study, the angle difference from the innermostportion to the outermost portion is desirable to be between 10° to 25°,and hence the value P of 1/2×(sin(P1)+sin(P2)) is preferable to besubstantially 0.175 to 0.423.

With the above-mentioned arrangement, as shown at numeral 11 in FIG. 7,the magnetic position of the MR read element 10 can be corrected so thatthe magnetic center line 20 thereof get closer by a distance 14 to thecenter line of the data track 8 as compared with the center line 29 ofthe magnetic position 12. This correction can halve the above-mentionedoffset to be about 1 micron according to the calculation under theabove-mentioned conditions. This value can substantially correspond tothe side guard band of the integrated head and almost allows reading theID sector without off-track in the write/read modes to thus improve theread error irrespective of a large yaw angle. As a result thisarrangement, the off-track amount becomes at a minimum (about zero) atthe vicinity of a middle point between the outermost and innermostpositions of the disk and increases in accordance with the movement ofthe integrated head 1 toward the innermost and outermost positions ofthe disk along the track crossing directions. Although taking differentsigns, the absolute values of the offsets (maximum values) of the MRread element 10 at the outermost and innermost positions of the disksubstantially become equal to each other.

The off-track characteristic in the write/read modes according to theembodiment of this invention will be described with reference to FIGS. 8to 10 wherein numeral 32 to 34 represent first to third servo patterns,respectively, 35 and 36 designate first and second informationidentification (ID) fields, respectively, 37 and 38 denote first andsecond data fields, respectively, and 41 expresses the off-track betweenthe inductive write element 2 and the MR read element 10 in the writemode. The description will be made under the representative conditionsthat the track pitch=6.2 μm, write track width=6.2 μm, MR read elementtrack width=3.6 μm, separation between the inductive write element gapand the MR read element=7.4 μm, yaw angle at the vicinity of theinnermost track=0°, and yaw angle at the vicinity of the outermosttrack=15°. The descriptions of other embodiments to be describedhereinafter will be made under the same conditions. Under theseconditions, according to this embodiment, the offset amount between themagnetic center lines 28 and 20 of the inductive write element 2 and theMR read element 10 becomes about 1 μm. FIG. 8 shows the relationship inposition between the inductive write element 2 and the MR read element10 at the vicinity of the innermost track wherein (a) indicates thepositional relationship in the read mode (the inductive write element 2is omitted) and (b) represents the positional relationship in the writemode or at the time of switching between the write/read modes for anadjacent sector. As illustrated in (a) of FIG. 8, for minimizing theoff-track in the read mode the magnetic center line 20 of the MR readelement 10 is required to be coincident with the center line of thesecond data field 38, and as illustrated in (b) of FIG. 8, when takingan on-track state in the write mode, the center line 28 of the inductivewrite element 2 is coincident with the center line of the first datafield 37. When generally performing the write operations, the ID fieldwhich includes sector information and cylinder information is requiredto be recognized by the MR read element 10 before recording data, andhence the MR read element 10 is required to simultaneously maintain theon-track state over at least the ID field even at the time that theinductive write element 2 is in the on-track state. According to thisembodiment, since the offset amount is only about 1 μm, considering thewidth of the track the MR read element 10 can also take the on-trackstate over the first ID field 35, thereby preventing reproductionerrors. Here, when performing the head positioning on the basis ofsector servo information or the like during these operations, asingle-phase position error signal consisting of the first and secondservo patterns 32 and 33 is used in the write mode, and in this case thepositioning is carried out so that the offset is 0.5 μm. Similarly inthe read mode the positioning is carried out on the basis of the secondand third servo patterns 33 and 34 so that the offset is 0.5 μm in theopposite direction.

Secondly, in FIG. 9 illustrating the head positions when performing thewrite/read operations at the vicinity of a middle track on the disk, inthe read mode (the inductive write element 2 is omitted as well as inFIG. 8), the physical yaw angle becomes 7.5°, while the center line 20of the magnetic position 27 of the MR read element 10 is coincident withthe center line 28 of the inductive write element 2. Thus, in both thewrite and read modes the off-track margins become at a maximum withrespect to the ID field and data field.

Further, FIG. 10 illustrates the head positions when performing thewrite/read operations for the adjacent tracks at the vicinity of theoutermost position of the disk. Although in this case the yaw anglebecomes as large as 15°, the magnetic position 27 of the MR read element10 takes the off-track state only by 1 μm toward the inner side of thedisk when viewed from the inductive write element 2, thus giving asufficient off-track margin with respect to the first ID field 35 andthe first data field 37.

Secondly, a modification of the above-mentioned first embodiment of thisinvention will be described below as a second embodiment of thisinvention. Although in the first embodiment the arrangement is made onthe basis of the magnetic relationship between the inductive writeelement 2 and the MR read element 10, in the second embodiment it isdetermined on the basis of the geometric offset between the inductivewrite element 2 and the MR read element 10. As described above, in theinductive write element 2, the magnetic center line is substantiallycoincident with the geometric center line, while in the MR read element10 they are not coincident with each other and deviated from each otherin the off-track directions (track crossing directions) because themagnetic flux reading direction is inclined by a certain angle(generally 45°) with respect to the ABS 19. However, the deviation ofthe magnetic center line of the MR read element 10 from the geometriccenter line thereof is known to be substantially 1/4 of the MR readelement height 40 from the ABS 19 as illustrated in FIG. 11 and,although the deviation amount is constant, the deviating directioninverts from the inner side of the disk to the outer side thereof orvise versa along the track crossing directions in accordance with thedirection (polarity) of the signal detection sense current flowing inthe MR read element 10. Accordingly, the arrangement of the integratedhead 1 can be made using the MR read element height 40 on the basis ofthe relationship in geometric position between the inductive writeelement 2 and the MR read element 10 instead of the relationship inmagnetic position therebetween. The relationship in geometric positionbetween the inductive write element 2 and the MR read element 10 in thissecond embodiment can be defined as follows in accordance with the sensecurrent direction. That is, the geometric offset between the inductivewrite element 2 and the MR read element 10 is defined as a valueobtained by multiplying 1/2 of the sum of the sine of the slider yawangle P1 at the innermost track and the sine of the slider yaw angle P2at the outermost track by the separation 9 between the magnetic gap 5 ofthe inductive write element 2 and the center of the MR read element 10and by adding 1/4 of the MR read element height 40 to the result of themultiplication. Further, the geometric offset therebetween can bedefined to be a value obtained by multiplying 1/2 of the sum of the sineof the slider yaw angle P1 at the innermost track and the sine of theslider yaw angle P2 at the outermost track by the separation 9 betweenthe magnetic gap 5 of the inductive write element 2 and the center ofthe MR read element 10 and by subtracting 1/4 of the MR read elementheight 40 from the result of the multiplication. When expressing thegeometric offsets OFFSET by equations, they become as follows.

    OFFSET=1/2×{sin (P1)+sin (P2)}×S+1/4×H   (2)

    OFFSET=1/2×{sin (P1)+sin (P2)}×S-1/4×H   (3)

where: sin(P1)=the sine of the slider yaw angle P1 at the innermosttrack; sin(P2) the sine of the slider yaw angle P2 at the outermosttrack; S=the separation between the magnetic gap 5 of the inductivewrite element 2 and the MR read element 10; and H=the height of the MRread element 2.

When 1/2×{sin(P1)+sin(P2)} is defined as an angle offset value P as wellas in the above-mentioned equation (1), the equations (2) and (3)becomes P×S+1/4×H and P×S-1/4×H.

Here, the integrated head 1 can be arranged so that the result of amultiplication of 1/2 of the sum of the sine of the slider yaw angle P1at the innermost track and the sine of the slider yaw angle P2 at theoutermost track by the separation S between the magnetic gap 5 of theinductive write element 2 and the center of the MR read element 10 isequal to 1/4 of the height H of the MR read element 5 to satisfy thefollowing equation (4):

    1/2×{sin (P1)+sin (P2)}×S=1/4×H          (4)

In this case, from the above-mentioned equation (3), the offset OFFSETbetween the geometric center lines of the inductive write element 2 andthe MR read element 10 substantially becomes zero.

As well as the above-described first embodiment this second embodimentdetermines the positional relationship in the track crossing directionsbetween the inductive write element 2 and the MR read element 10 on thebasis of the head slider skew and can provide the effect similar to thatof the first embodiment.

Further, a description of a third embodiment of this invention will bedescribed below with reference to FIG. 12. This third embodiment is forcompensating for the offset problem between the inductive write element2 and the MR read element 10 with an arrangement of a disk track. Morespecifically, the relationship in position between informationidentification fields and data fields of tracks on a disk is make inconnection with the relationship in magnetic position between theinductive write element 2 and the MR read element 10 in the trackcrossing directions as illustrated in FIG. 5. FIG. 12 schematicallyillustrates a track layout of a disk of a rotary cylinder according tothe third embodiment of this invention and showing three tracks at eachof three representative portions of the disk. Here, the threerepresentative portions of the disk mean the innermost portion coveringabout 10 tracks including the innermost track (n), the middle portionranging over about 10 tracks including the middle track (k) and theoutermost portion comprising about 10 tracks including the outermosttrack (0). In accordance with the general manner the tracks are numberedas the number of the outermost rack is (0). In FIG. 12, each of thetracks comprises a first servo signal field 101, a second servo signalfield 102, an information identification field 103 and a data field 104.The information identification field 103 is provided for identificationsof track information, sector information and others. The outermost track(0) exists on a line where the level of the position error signal fromthe first and second servo signal fields 101 and 102 becomes the lowest,and the line passes through the center of the information identificationfield 103. Between the line and the center line 120 of the data field104 of the outermost track (0) there is made a deviation 118corresponding to a positional difference between the data andinformation identifier of the outermost track (0). The deviation 118 ismade so that the information identification field 103 is shifted towardthe inner side when being viewed from the data field 104. The value ofthe deviation 118 is determined on the basis of the relationship inmagnetic position between the inductive write element 2 and the MR readelement 10 at the outermost track (0) so as to get an adequate off-trackcharacteristic. Further, in the middle track (k) a deviation is alsomade between a data field 104 and an information identification field103. That is, in the middle track (k) the center line 202 of the datafield 104 is shifted by a distance 201 from the center line of theinformation identification field 103 so that the information identifieris shifted toward the inner side when viewed from the data field 104.This deviation 201 is set to be smaller than the above-mentioneddeviation 118. On the other hand, in the innermost track (n) the centerline of the information identification field 103 is arranged to becoincident with the center line of the data field 104. That is, thedeviation is set to be zero. Here, as obvious from the abovedescription, taking into account the fact that the slider yaw anglevaries in accordance with the positions of the disk, the deviationbetween the information identification field 103 and the data field 104is arranged to successively vary in accordance with the positions of thedisk. Thus, the deviations are made in accordance with the positionaloffsets in the track crossing directions between magnetic center linesof the inductive write element 2 and the MR read element 10 on the disk.

FIG. 13 shows deviations between the information identification fields103 and the data fields 104 at every position of the disk, where adeviation 125 for the track (i) is shown in addition to theabove-mentioned deviations 118 and 201 for the outermost track (0) andthe middle track (k). As shown in FIG. 13, the respective deviations aredetermined by the linear interpolation after determining, for example,the deviation of the outermost track and the deviation of the innermosttrack (which is zero in this embodiment). When taking into account thehead positioning servo revolving power and the fact that the variationof the deviation is extremely small because a large number of tracks areprovided for improvement of the recording density, it is possible thatthe deviations can be made to successively vary stepwise in accordancewith the linear interpolation. Here, the deviations are not alwaysrequired to be determined completely in accordance with the linearinterpolation and each of data zones on the disk which are divided onthe basis of the recording/reproducing frequency or the like can also bearranged to have a constant deviation so that the deviationssuccessively vary stepwise in accordance with the linear interpolationas a whole. In this case, the average deviation of each data zone istreated as a typical value.

For recognizing the information identification field 103 the MR readelement 10 is required to take an on-track state on the informationidentification field 103 as accurately as possible, and in theinformation recording mode the information identification field 103 isrequired to be recognized by the MR read element 10 immediately beforerecording data at a predetermined place. However, the time periodallowed for the data recording after the recognition of the informationidentification field is short and hence difficulty is actuallyencountered to mechanically compensate for the above-mentionedpositional deviation between the inductive write element 2 and the MRread element 10. According to the third embodiment the informationidentification fields 103 are shifted to the inner side of the disk withrespect to the data fields 104, and hence, even if the yaw angle islarge, the recording can be carried out by the inductive write element 2immediately after recognizing the information identifier.

Further, a description of a fourth embodiment of this invention will bemade with reference to FIG. 14 showing another track layout on a disk. Afeature of this fourth embodiment is that the deviations are arranged tovary so as to increase in the opposite direction to that of theabove-described third embodiment. In FIG. 14, the innermost track (n) ison a line where the level of the position error signal from first andsecond servo signal fields 101 and 102 becomes the lowest, and the linepasses through the center of the information identification field 103.Between the line and the center line 119 of the data field 104 of theinnermost track (n) there is a deviation 117 which is a positionaldifference between the data and an information identifier. The deviation117 is made so that the information identification field 103 is shiftedtoward the outer side with respect to the data field 104. Further, inthe middle track (k) a deviation is also made between the data field 104and information identification field 103. That is, the center line 202of the data field 104 is shifted from the center line of the informationidentification field 103 by a distance 201 set to be smaller than theabove-mentioned deviation 117. On the other hand, in the outermost track(0) the center line of the information identification field 103 isarranged to be coincident with the center line of the data field 104.This means that the deviation here becomes zero, and if the magneticcenter of the MR read element 10 is arranged to be coincident with thecenter line of the data track, it is obvious that the off-track betweenthe inductive write element 2 and the MR read element 10 does not occurat the outermost position.

As well as the above-described third embodiment the respectivedeviations can be determined by the linear interpolation afterdetermining the deviation 117 of the innermost track and the deviationof the outermost track (which is zero in this embodiment) as illustratedin FIG. 15 so as to be in relation to or substantially in proportion tothe magnetic differences between the inductive write element 2 and theMR read element 10. Here, the deviations are not always required to bedetermined completely in accordance with the linear interpolation andeach of data zones on the disk which are divided on the basis of therecording/reproducing frequency or the like can also be arranged to havea constant deviation so that the deviations successively vary stepwisein accordance with the linear interpolation as a whole.

A description of a fifth embodiment of this invention will be made withreference to FIG. 16. A feature of this fifth embodiment is that thedeviations are arranged to vary to increase from the middle portion of adisk toward the innermost and outermost portions thereof. In FIG. 16,similarly the innermost track (n) is on a line where the level of theposition error signal from first and second servo signal fields 101 and102 becomes the lowest, and the line passes through the center of theinformation identification field 103. Between the line and the centerline 119 of the data field 104 of the innermost track (n) there is adeviation 117 which is a positional difference between the data and aninformation identifier. The deviation 117 is made so that theinformation identification field 103 is shifted toward the outer sidewith respect to the data field 104. Further, in the outermost track (0)a deviation 118 is set between the center line 120 of the data field 104and the center line of the information identification field 103. On theother hand, in the middle track (k) the center line of the informationidentification field 103 is arranged to be coincident with the centerline of the data field 104. The deviation here is zero.

According to this fifth embodiment, the off-track between the inductivewrite element 2 and the MR read element 10 at the innermost andoutermost portions of the disk can be reduced as compared to the values(about 2 microns under the above-mentioned conditions) in the third andfourth embodiments. The off-track amount at the innermost portion can beset between zero and the result of a multiplication of the separation(the distance between the magnetic gap 5 of the inductive write element2 and the center of the MR read element 10) S by the sine of the slideryaw angle P1 at the innermost portion, and the off-track amount at theoutermost portion can be set to be between zero and the result of amultiplication of the separation S by the slider yaw angle P2 at theoutermost portion. Thus, when the absolute values of the deviations ofthe information identification fields 103 at the innermost and outermostportions are arranged to be equal to each other and the deviationsthereof are arranged to be 1/2 of the offset amount in the trackcrossing directions between the magnetic center lines of the inductivewrite element 2 and the MR read element 10, it is possible to mostreduce the deviations between the information identification field andthe data field to thereby minimize the off-track of the MR read element10 at the time of recognizing the information identifier in the bothrecording and reproduction modes. This will be obvious comparing FIG. 17with FIGS. 13 and 15 mentioned above.

Referring to FIG. 17 showing the deviations determined with the linearinterpolation in the fifth embodiment, the absolute values of thedeviations 117 and 118 at the innermost track (n) and outermost track(0) are set to be equal to each other. In addition, in the magneticpositional relationship between the inductive write element 2 and the MRread element 10 in the track crossing directions, the absolute valuesOFFSET become equal to the result of a multiplication of 1/2 of the sumof the sine sin(P1) of the slider yaw angle P1 and the sine sin(P2) ofthe slider yaw angle P2 by the separation S. That is,OFFSET=1/2×{sin(P1)+sin(P2)}×S, and when 1/2×{sin(P1)+sin(P2)} isdefined as P (angle offset), OFFSET=P×S.

Here, as well as the above-described first embodiment, according to astudy, the angle variation from the innermost portion to the outermostportion is desirable to be between 10° to 25°, and hence the angleoffset value is set to be 0.175 to 0.423.

FIG. 18 shows the fifth embodiment applied to a magneticrecording/reproduction system having a head-positioning servo surface ona disk for describing the relationship in position between servo surfaceservo signal fields and information identification fields.

In this system, a magnetic recording surface for servo only is providedand the positioning information is read by a servo head equipped on themagnetic recording surface. In FIG. 18, numerals 121 to 124 denote servosurface servo signal fields, respectively. Although actually existing ona special servo surface different from the data surface including thedata fields and the information identification fields, they are showntogether with the data surface for description only. The servo signalfields 121 to 124 are formed in the servo surface and arrangedsuccessively at an equal pitch so that a center line of each of theservo signal fields 121 to 124 at which a position error signal from theservo head shows a minimum is coincident with the center line of each ofthe information identification fields. This pitch is different from thepitch of the data fields in the data surface, while the servo signalpitch is arranged to be the same as the pitch of the informationidentification fields and servo signal fields in the data surface andhence the head positioning can easily be realized by minimizing theposition error signal. Although being also effective for such a servosurface type recording/reproduction system, the above-described third tofifth embodiments can take effect with only the servo signals in thedata surface regardless of the servo surface.

According to the above described third to fifth embodiments, withoutsetting the information identification fields and the data fields oftracks on the same lines, the relationship in position between theinformation identification fields and the data fields is made inconnection with the relationship in position between the inductive writeelement and the MR read element in the track crossing directions so thatthe information identification fields are shifted by predeterminedquantities from the data fields. These deviations between theinformation identification fields and the data fields successively varytoward the innermost or outermost portion of the disk or toward both theinnermost and outermost portions. These arrangements allow preventingthe recognition of the information identification fields from loweringdue to the off-track between the inductive write element and the MR readelement and further allows reducing the reproduction errors andimproving the throughput.

It should be understood that the foregoing relates to only preferredembodiments of the present invention, and that it is intended to coverall changes and modifications of the embodiments of the invention hereinused for the purposes of the disclosure, which do not constitutedepartures from the spirit and scope of the invention.

What is claimed is:
 1. A recording and reproduction apparatus operablewith at least one disk, having an innermost portion and an outermostportion, serving as a recording medium having a plurality of tracks andcomprising an integrated head for recording and reproducing data on andfrom said disk, said integrated head comprising write element means forwriting said data on said disk and read element means for reading saiddata and necessary information from said disk and being mounted on ahead slider which is arranged to be rotatable about a point so as to berotationally accessible to said disk to make yaw angles with respect totangents of said tracks, wherein each of said plurality of trackscomprises an information identification field and a data field, whereincenter lines of said information identification fields which extend indirections perpendicular to track crossing directions are shifted bypredetermined distances from center lines of said data fields whichextend in directions perpendicular to said track crossing directions soas to make deviations in said track crossing directions between saidcenter lines of information identification fields and said center linesof said data fields, said deviations being substantially determined inaccordance with the positional relationship in said track crossingdirections between magnetic center lines of said write element means andsaid read element means on said disk so as to vary successively, whereinthe deviation between the information identification field and the datafield in the track of the innermost portion of said disk is set to bezero and the deviation therebetween in the track of the outermostportion of said disk is made toward an inner side of said disk and seton the basis of a difference between said magnetic center lines of saidwrite element means and said read element means at the outermost portionthereof, and said deviations at intermediate portions between theinnermost and outermost portions are determined so as to varysuccessively to substantially increase from the innermost portion to theoutermost portion, and wherein said deviations at said intermediateportions are determined with a linear interpolation between saiddeviations in the tracks of the innermost and outermost portions.
 2. Arecording and reproduction apparatus operable with at least one disk,having an innermost portion and an outermost portion, serving as arecording medium having a plurality of tracks and comprising anintegrated head for recording and reproducing data on and from saiddisk, said integrated head comprising write element means for writingsaid data on said disk and read element means for reading said data andnecessary information from said disk and being mounted on a head sliderwhich is arranged to be rotatable about a point so as to be rotationallyaccessible to said disk to make yaw angles with respect to tangents ofsaid tracks, wherein each of said plurality of tracks comprises aninformation identification field and a data field, wherein center linesof said information identification fields which extend in directionsperpendicular to track crossing directions are shifted by predetermineddistances from center lines of said data fields which extend indirections perpendicular to said track crossing directions so as to makedeviations in said track crossing directions between said center linesof information identification fields and said center lines of said datafields, said deviations being substantially determined in accordancewith the positional relationship in said track crossing directionsbetween magnetic center lines of said write element means and said readelement means on said disk so as to vary successively, wherein thedeviation between the information identification field and the datafield in the track of the outermost portion of said disk is set to bezero and the deviation therebetween in the track of the innermostportion of said disk is made toward an outer side of said disk and seton the basis of a difference between said magnetic center lines of saidwrite element means and said read element means at the innermost portionthereof, and said deviations at intermediate portions between theoutermost and innermost portions are substantially determined so as tovary successively to substantially increase from the outermost portionto the innermost portion, wherein said deviations at said intermediateportions are substantially determined with a linear interpolationbetween said deviations in the tracks of the innermost and outermostportions.
 3. A recording and reproduction apparatus operable with atleast one disk, having an innermost portion and an outermost portion,serving as a recording medium having a plurality of tracks andcomprising an integrated head for recording and reproducing data on andfrom said disk, said integrated head comprising write element means forwriting said data on said disk and read element means for reading saiddata and necessary information from said disk and being mounted on ahead slider which is arranged to be rotatable about a point so as to berotationally accessible to said disk to make yaw angles with respect totangents of said tracks, wherein each of said plurality of trackscomprises an information identification field and a data field, whereincenter lines of said information identification fields which extend indirections perpendicular to track crossing directions are shifted bypredetermined distances from center lines of said data fields whichextend in directions perpendicular to said track crossing directions soas to make deviations in said track crossing directions between saidcenter lines of information identification fields and said center linesof said data fields, said deviations being substantially determined inaccordance with the positional relationship in said track crossingdirections between magnetic center lines of said write element means andsaid read element means on said disk so as to vary successively, whereinthe deviation between the information identification field and the datafield in the track of the outermost portion of said disk is set tocorrespond to a difference between said magnetic center lines of saidwrite element means and said read element means at the outermost portionand is made toward an inner side of said disk, and the deviationtherebetween in the track of the innermost portion is set on the basisof a difference between said magnetic center lines of said write elementmeans and said read element means at the innermost portion and is madetoward an outer side of said disk, the absolute values of saiddeviations in the tracks of the innermost and outermost portions beingsubstantially equal to each other, and said deviation in the track of amiddle portion of said disk is set to be zero and deviations in thetracks of intermediate portions between the middle portion and one ofthe innermost and outermost portions are determined so as to varysuccessively to substantially increase from the middle portion to theinnermost and outermost portions, wherein the absolute values of saiddeviations in the tracks of the innermost and outermost portions aredetermined as a function of 1/2 of a difference between the magneticcenter lines of said write element means and said read element means atthe innermost and outermost portions of said disk, wherein the absolutevalues of said deviations in the tracks of the innermost and outermostportions are determined on the basis of a value OFFSET obtainedaccording to the following equation:

    OFFSET=1/2×{sin (P1)+sin (P2)}×S

where: P1=the slider yaw angle with respect to the tangent of theinnermost track; P2=the slider yaw angle with respect to the tangent ofthe outermost track; sin(P1)=the sine of the slider yaw angle P1;sin(P2)=the sine of the slider yaw angle P2; and S=a separation betweena gap of said write element means and a center of said read elementmeans.
 4. A recording and reproduction apparatus as claimed in claim 3,wherein a value of 1/2×{sin(P1)+sin(P2)} is set to be 0.175 to 0.423. 5.A recording and reproduction apparatus operable with at least one disk,having an innermost portion and an outermost portion, serving as arecording medium having a plurality of tracks and comprising anintegrated head for recording and reproducing data on and from saiddisk, said integrated head comprising write element means for writingsaid data on said disk and read element means for reading said data andnecessary information from said disk and being mounted on a head sliderwhich is arranged to be rotatable about a point so as to be rotationallyaccessible to said disk to make yaw angles with respect to tangents ofsaid tracks, wherein each of said plurality of tracks comprises aninformation identification field and a data field, wherein center linesof said information identification fields which extend in directionsperpendicular to track crossing directions are shifted by predetermineddistances from center lines of said data fields which extend indirections perpendicular to said track crossing directions so as to makedeviations in said track crossing directions between said center linesof information identification fields and said center lines of said datafields, said deviations being substantially determined in accordancewith the positional relationship in said track crossing directionsbetween magnetic center lines of said write element means and said readelement means on said disk so as to vary successively, wherein thedeviation between the information identification field and the datafield in the track of the outermost portion of said disk is set tocorrespond to a difference between said magnetic center lines of saidwrite element means and said read element means at the outermost portionand is made toward an inner side of said disk, and the deviationtherebetween in the track of the innermost portion is set on the basisof a difference between said magnetic center lines of said write elementmeans and said read element means at the innermost portion and is madetoward an outer side of said disk, the absolute values of saiddeviations in the tracks of the innermost and outermost portions beingsubstantially equal to each other, and the deviation in the track of amiddle portion of said disk is set to be zero and deviations in thetracks of intermediate portions between the middle portion and one ofthe innermost and outermost portions are determined so as to varysuccessively to substantially increase from the middle portion to theinnermost and outermost portions, wherein said deviations in the tracksof intermediate portions between the middle portion and one of theinnermost and outermost portions are determined with a linearinterpolation between said deviations in the tracks of the innermost andoutermost portions and said deviation in the track of said middleportion.